/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 *  kernel/mqueue/mq_descreate.c
 *
 *   Copyright (C) 2007-2009, 2013, 2016 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>

#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <assert.h>
#include <mqueue.h>
#include <sched.h>
#include <queue.h>
#include <debug.h>

#include <tinyara/arch.h>
#include <tinyara/kmalloc.h>
#include <tinyara/sched.h>
#include <tinyara/mqueue.h>

#include "signal/signal.h"

#include "mqueue/mqueue.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Type Declarations
 ****************************************************************************/

/****************************************************************************
 * Public Variables
 ****************************************************************************/

/****************************************************************************
 * Private Variables
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: mq_desalloc
 *
 * Description:
 *   Allocate a message queue descriptor.
 *
 * Inputs:
 *   None
 *
 * Return Value:
 *   Reference to the allocated mq descriptor.
 *
 ****************************************************************************/

static mqd_t mq_desalloc(void)
{
	mqd_t mqdes;

	/* Try to get the message descriptorfrom the free list */

	mqdes = (mqd_t)sq_remfirst(&g_desfree);

	/* Check if we got one. */

	if (!mqdes) {
		/* Add another block of message descriptors to the list */

		mq_desblockalloc();

		/* And try again */

		mqdes = (mqd_t)sq_remfirst(&g_desfree);
	}

	return mqdes;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: mq_descreate
 *
 * Description:
 *   Create a message queue descriptor for the specified TCB
 *
 * Inputs:
 *   mtcb   - task that needs the descriptor.
 *   msgq   - Named message queue containing the message
 *   oflags - access rights for the descriptor
 *
 * Return Value:
 *   On success, the message queue descriptor is returned.  NULL is returned
 *   on a failure to allocate.
 *
 ****************************************************************************/

mqd_t mq_descreate(FAR struct tcb_s *mtcb, FAR struct mqueue_inode_s *msgq, int oflags)
{
	FAR struct task_group_s *group;
	mqd_t mqdes;

	/* A NULL TCB pointer means to use the TCB of the currently executing
	 * task/thread.
	 */

	if (!mtcb) {
		mtcb = sched_self();
	}

	group = mtcb->group;
	DEBUGASSERT(group);

	/* Create a message queue descriptor for the TCB */

	mqdes = mq_desalloc();
	if (mqdes) {
		/* Initialize the message queue descriptor */

		memset(mqdes, 0, sizeof(struct mq_des));
		mqdes->msgq = msgq;
		mqdes->oflags = oflags;

		/* And add it to the specified task's TCB */

		sq_addlast((FAR sq_entry_t *)mqdes, &group->tg_msgdesq);
	}

	return mqdes;
}
